my 2001 silverado 2500HD radio, heater fan, dash, etc. all internal power stays on after i turn the truck off, take the key out and open the door. the engine turns off but everything else stays on. the cabin heater fan stays on no matter what setting the switch is on even when it is switched to off. Help!

 

a list all the items that stay on...cluster lights, wipers, radio etc and the ones that do not...this saves me time diagnostically.

 

It could be RAP, but I'd try pulling the blower motor relay, Im wondering if the relay is staying engaged (stuck due to burned contact, arcing) and is back feeding the whole circuit....